heat sink question

[mendozer]

Looking to make my panel soon and I was wondering if there can ever be too big of a heatsink.

I need 40A but the only ones I see that cover the hole of the enclosure I want are 60A. I assume no but just thought I'd ask if there's a weird thermodynamic thing to be observed. Note: I'll be running 22.92A at full capacity so I'm already over the 30% buffer on my parts.

 

[doug293cz]

If you can't lift it, or it rips the panel mounting screws out of the wall, then it's too big. Otherwise, there is no issue with using more heatsink than you need.

Brew on

 

[mendozer]

can't lift it? I assume this is screwed to the panel top and pasted onto the SSR.

 

[doug293cz]

can't lift it? I assume this is screwed to the panel top and pasted onto the SSR.

Guess I should have put "humor" tags around the first sentence. Bigger is better, up to the point of ridiculousness.

Brew on

 

[mendozer]

oh ok haha. I kind of sensed sarcasm but wasn't sure.

 

[kal]

Looking to make my panel soon and I was wondering if there can ever be too big of a heatsink.

Nope. The cooler you run electronics, the better. That's why I went "overkill" myself:

Kal

 

[RichBenn]

What I did was kind of in between what Kal did and the stock heat sinks sold with SSRs.

The most important factors are contact with the heat sink, ambient temperature and the ability to dissipate heat. Contact should be using a good thermal grease. After that, if at room temperature, and the stock heat sink is exposed free air, then you are probably OK. Anything more will require a bigger heat sink and/or forced air(a fan) across the fins.